Rotary toothbrush



Jan. 14, 1941. L. D. STONER ROTARY TOOTHBRUSH Filed Jan. 20, 1939 vae" Patented Jan. 14, 1941 Y UNITED STATES PATENT AoI-FicE 2,228,786I ROTARY Too'rnBaUsH Lewis Duane Stoner, San Francisco, Calif. Applicationranuary zo, 1939, serial No. 251,933

Y 6 Claims. (ci. 15-25) The present invention relates to toothbrushes and more particularly to a new and novel toothbrush of the so-called rotary type.

An object of the invention is to provide a. new and novel form of toothbrush of the rotary type. that is adapted to be held and operated with one hand.

Another object of the invention is to provide a simple and inexpensive form of toothbrush which may be easily and economically constructed of molded plastic material or die cast in metal.

Another object of the invention is to provide a rotary toothbrush of sanitary construction in which the parts are assembled to provide for an effective cleansing thereof in a stream of water.

Another object of the invention is to provide in a rotary toothbrush an arrangement by which the g several parts may be quickly assembled or disassembled in a simple and convenient manner.

Other objects and advantages of the invention will be in part pointed out hereinafter and in part evident to thoseskilled in the art as the descrip-4 tion thereof proceeds.

In the accompanying drawing wherein there is shown by way of illustration and not of limitation preferred embodiments of the invention;

Figure 1 is a side elevation showing the irnproved rotary toothbrush as contemplated by my invention.

Figure 2 is a plan .view of the toothbrush illustrated in Fig. i, l

Figure 3 is a vertical sectional view taken through the toothbrush as illustrated in Fig. 1.

Figure 4 is a fragmentary vertical sectional view showing modied details of a brush constructed vin accordance with this invention,

Figure 5 is a slightly enlarged transverse sectional view taken along line V-V of Fig. 2 and showing the contour of the mouth guard,

Figure 6 is a slightly enlarged transverse sectional view taken along line VI-VI of Fig. 2 showing the construction of the toothbrush frame at this point, land Figure 7 is a similarly enlarged transverse sectional view taken along line VII-'VII of Fig. 2 and showing, in dot and dash lines, the thumb and finger of an operator as applied thereto.

In the drawing the invention is illustrated asl substantially in full size. As shown in Figures 1 and 2 of the drawing, the brush as a whole comprises a supporting frame Ill having a mouth guard II formed integrally at one end thereof and a grip forming handle I2 at its other end. While the frame I0 is preferably formed with the mouth guard I I integrally therewith, it will be understod that this mouth guard can `be formed as a separate piece and secured in any convenient 1 manner upon the frame I0. The handle I2 likewise may be formed as an integral part of the frame III if so desired. As shown, the supporting `5 frame has an intermediate bearing I3 and end bearings I 4 and I5. The bearings I3 and It serve as a support for a shaft I6 upon the end of which there is secured a tooth cleaning brush Il of any suitable type. As shown, this brush Il is ofthe twisted wire type. The contour of the brush bristles is preferably somewhat barrelled, as is also the contour of the mouth guard I I. Between the bearings I3 and It, the frame I@ is formed as two spaced struts I8 thatextend parallel to and in spaced relation with the shaft i6 to connect the bearings I3 and Ifl together as a unit. These struts I 8, by providing an opening in the frame I0 along the shaft I6, eliminate what would otherwise be a continuous bearing about the shaft I 6 in which an accumulation of foreign matter might occur and which would be difiicult to clean. En their preferred form, these struts i8, as will hereinafter appear, are of streamlined cross-section so that any accumulation along the shaft IS between the bearings I3 and It may be readily washed out with a stream ofwater.

At the end of theshaft It and disposed between the intermediate bearing I3 and the end bearing I5 there is a knurled means I9 by means of Vwhich the shaft IG and the brush Il may be rotated when engaged by the thumb and nger of the user. As shown. the knurled means I9 is disposed within an elongated aperture 2@ formed between the intermediate bearingl I 3 and the bearing I5. Extending along each side of the aperture 20 vand connecting the bearings I3 and l are two oppositely disposed `outwardly extending webs 2i and 22 that are adapted to be engaged by the padded part of the thumb and nger ofthe operator while operating upon the knurled means I9, as will be hereinafter pointed out.

Upon referring to Figure 3 of the drawing it will be noted that the struts I8 between the bearings I3 and I4 provide an open support with relatively short bearing surfaces for the shaft I6. This avoids vexcessive friction and at the same time prevents the accumulation of any excessive tooth cleaning paste or powder along the shaft such as would occur were the shaft extended through a s'olid frame. As here illustrated, the shaft I6 terminates in the aperture '20 formed between the connecting webs/ 2I and 22 where the knurled means I9 is attached thereto. The shaft and brush rotating means I 9 is secured to the extending end of the shaft I6 and at its other end this rotating means I9 is journalled upon a relatively short stub shaft 22 that is carried by the bearing I6. In this arrangement the bearing I6 is shown as having an outwardly extending portion 2l upon which the grip forming handle I2 is threaded. Ihis provides an arrangement by which the stub shaft 23 may be conveniently inserted and secured in the bearing I5 after the knurled means I9 has been mounted upon the shaft I6. While the knurled means I9 may take any desirable form and size, it is here illustrated as what may be termed a chuck which has a diameter substantially larger than the greatest thickness of the connecting webs 2| and 22.

Reference is now made to Figure 4 of the drawing for a detailed description of the specific form of shaft rotating means I9 described above. In this figure of the drawing, the parts illustrated are somewhat enlarged and the brush supporting shaft, designated by the numeral 2l, is shown as extending completely through the aperture 20 of the frame III and into a handle forming portion 25 which is an integral part of the frame I0. The knurled shaft driving means I9 here illustrated is similar to that shown in Figure 3 and may be described as comprising two axially arranged and externally knurled portions 26 and 2'I. 'I'he knurled portion 26 has a reduced threaded portion 28 and two or more outwardly extending springable jaws 29 that extend into the portion21. Co-

operating with the reduced threaded portion 2li of the knurled portion 26 the portion 2'I has an internally threaded end 30 and a reduced portion 3l that is adapted to engage and press the springable jaws 29 into gripping relation with the shaft I6 and/or 24 in a manner similar to that obtained in a simple drill chuck.

In Figure 5 of the drawing, the mouth guard I I in addition to being barrelled is also shown as having a curved contour which follows the curvature of the bristles of the brush II.

Upon referring to Figure 6 of the drawing, it will be noted that the struts I6 of the frame III which connect the bearings I3 and I4 together have a streamlined cross-section, the major axis of which extends substantially vertical and the major transverse axis of which is substantially on the horizontal center line of the shaft I6. With this arrangement the trailing edges of these struts I8 will provide a streamlined clearance between the struts and the shaft I6 which will permit a thorough cleansing of the brush frame along the shaft I6 at this point and thus provide a practical and sanitary support for the rotatable shaft I6.

Reference is now made to Figure 7 of the drawing. As here illustrated, it will be noted that the outwardly extending webs 2i and 22 which connect the bearings I3 and I5 of the frame I0 are of a thickness substantially less than. the diameter of the knurled brush rotating means yI9. Therefore, when the latter means is engaged by the thumb and finger of the operator, the padded fleshy parts of the thumb andfinger of the operator will lightly engage these extending webs and slide thereover while at the same time they will permit a sufficient pressure and frictional engagement with the knurled means I9 to provide for an effective and positive application of force upon the knurled means I9 to produce a rotation of the shaft. I 6 and the brush I1 at the end thereof.

It is believed that the `operation of the brush constructed in accordance with this invention will be understood from the above description.

n will be noteditnathe grip forming handle is not of a size and,v length sumcient to accommodateall of the fingers of the hand of a user. This handle is of such a length and size as to be conveniently gripped between the heel and the third and fourth fingers of the hand so that the thumb and index finger will naturally be positioned over the knurled rotating means I9. When the brush is thus held by the operator, the frame I0 can be firmly held and at the same time the brush can be operated with the thumb and index finger by a reciprocating movement thereof, which will rotate and/or cscillate the rotating means I9 and thus also lthe brush I1. When the device is thus operated, the soft padded portions of the thumb and forefinger will flex downwardly at each side of the knurled rotating means I9 and engage the surfaces of the connecting webs 2i and 22 and thus hold the frame I0 against any turning movement in the hand. Should the operator now desire, for any reason, to change the position of the brush with respect to the teeth, as for example, to reverse the position of the guard so as to clean the inside of the teeth, the operator need only grip the outer edges of the webs 2I and 22 between the thumb and forenger and turn the entire frame over. The knurled means I9 can then be again engaged and operated in the manner described above.

While I have, for the sake of clearness and in order to disclose the invention so that the same can be readily understood, described and illustrated specific arrangements, I desire to have it understood that the invention is not limited to the specific means disclosed. For example, as has been suggested above, while the frame I0 is illustrated as comprising one complete integral unit, it isconceivable that this supporting frame may be made up with separate parts. It is also contemplated that the number of bearings for the shaft I6 may be reduced to two in number and that the invention may be embodied in many other ways that will suggest themselves to persons skilled in the art. It is believed that this invention is new and it is, therefore, desired to claim it so that all such changes as come Iwithin the scope of the appended claims are to be considered as a part of this invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A toothbrush of the character described, comprising a supporting frame having a mouth guard at one end and a grip forming handle at its other end, said frame having an elongated axially disposed aperture adjacent said grip forming handle, a shaft rotatably mounted upon said support having a brush at one end positionedv within said mouth guard and its other end projecting into said elongated aperture, said frame having relatively thin outwardly extending connecting portions along said elongated aperture that provide thumb and finger engaging surfacesy which are disposed substantially radial to the axis of said shaft, and a knurled means disposed within said aperture and secured to the end of said shaft adapted to be. rotated by the thumb and nger of an operator, said relatively thin connecting por- Itions of said frame being of such a thinness and of such radial dimensions that the thumb and finger of the operator will slide freely thereover and at the same time prevent a turning of said frame while said knurled means is being rotated.

2. A toothbrush of the rotary typecomprising a supporting frame having spaced bearings for a brush supporting shaft, a shaft having a brush secured at one end and extending between said bearings, and means at the other end of said shaft engageable by the thumb and finger of an operator for rotation of said brush, said frame between said bearings comprising spaced and oppositely disposed struts of streamlined crosssection, whereby any accumulation of foreign matter along said frame may be displaced by a stream of water when applied thereto.

3. In a toothbrush of the character described the combination of a supporting frame, said frame having a grip forming portion and an axially extending aperture intermediate its ends for the reception of a knurled brush operating means, a shaft having a brush at one end journalled in said frame and extending into said aperture, and a knurled means for rotating said brush adapted to be secured upon said shaft comprising a knurled portion having a reduced externally threaded portion and springable jaws extending outwardly therefrom and another knurled portion having an internally threaded portion and a jaw engaging portion adapted to engage and clamp the springable jaws of said rst portion upon said shaft when said portions are threaded upon each other, whereby said knurled means may be quickly and effectively applied to said shaft to secure the shaft upon said support.

4. In a rotary toothbrush of the character described the combination of a one piece frame having an intermediate and two end bearings, a brush supporting shaft extending through one of said end bearings and said intermediate bearing, said frame between the shaft supporting bear ings comprising two connecting struts disposed in spaced parallel relation with said shaft, a. grip forming handle secured upon said frame and extending outwardly from the other of said end bearings, a stub shaft mounted in said latter bearing, and a knurled cylindrical means journalled at one end upon said stub shaft and fixed at its other end upon said brush supporting shaft, whereby said brush may be rotated by a rolling of said knurled means between the thumb and finger of an operator.

5. In a rotary toothbrush of the character described, the combination of a frame having an intermediate and two end bearings, a brush supporting shaft extending through one of said end bearings and said intermediate bearing, a grip forming handle upon said frame extending outwardly from the other of said end bearings, a stub shaft mounted in said latter bearing, and an operating means journaled at one end upon said stub shaft and fixed at its other end upon said brush supporting shaft, whereby said brush may be rotated by a rolling of said operating means between the thumb and finger of a user.

6. In a rotary toothbrush of the character described, the combination of a frame having an aperture intermediate its ends with shaft supporting bearings at each end of said aperture, a, brush supporting shaft extending through one of said bearings and into said aperture, a grip forming handle upon said frame extending outwardly from the other of said bearings, a stub shaft mounted in said latter bearing, and an voperating means journaled at one end upon said stub shaft and. fixed at its other end upon said brush supporting shaft, whereby said shaft may be rotated by a rolling of said operating means between the thumb and finger of a user.

LEWIS DUANE STONER.. 

